Case Study: Developmental Physiology at High Altitude

Abstract

High altitude is a challenging environment mostly characterized by a low pressure of oxygen but also by cold temperatures, air dryness, reduced protection against exposure to solar radiations, and more limited resources than at lower altitudes. During postnatal development, energy requirements are elevated, and reduction of oxygen supply (hypoxia) during this period has profound physiological consequences. Different models of exposure to hypoxia in newborn mammals have been used over the years and have helped to establish the effects of hypoxia during development on the cardiorespiratory system. Exposure to hypoxia during postnatal development has long-term consequences that manifest throughout the life span. These consequences of neonatal hypoxia might help the adults to better withstand the effects of the reduced oxygen pressure or on the contrary impair the subsequent responses to hypoxia. Most experimental research on development at high altitude focuses on the hypoxic environment, and the cardiorespiratory system, while only few data are available concerning thermoregulatory processes, and the interactions between cold and hypoxia during postnatal development at high altitude. In summary developmental hypoxia determines the ability of adult mammals to withstand life at high altitude, and the available data indicate that this might be an important driving force in short-term acclimatization and long-term adaptation to high altitude. Developmental physiology at high altitude should therefore be considered as a central element for physiology and adaptation to this specific environment.